const {EventEmitter} = require('events');

let event = new EventEmitter();

event.once('some',(str) => {
    console.log('some——events1',str)
})

let callback = () => {
    console.log('some——events2')
}

event.on('some_event',callback)

// event.removeAllListeners('some')

event.emit('some','参数1')

event.emit('some_event')

// js  dom0  dom2

// onclick=  oninput=

//addeventListenter()  removeEveneListener